The United Kingdom has been forced to pause its planned agreement to transfer sovereignty of the Chagos Islands to Mauritius after U.S. President Donald Trump withdrew support for the deal, creating a major diplomatic setback for Prime Minister Keir Starmer’s government.
The agreement would have seen Britain hand over control of the Indian Ocean archipelago while retaining a long-term lease expected to last at least 99 years over the strategically vital island of Diego Garcia, home to a key joint UK-U.S. military base. However, the legislation required to finalize the transfer has now been removed from the government’s parliamentary agenda following Washington’s opposition.
Trump reportedly criticized the proposal as an “act of great stupidity,” arguing that transferring sovereignty risked weakening Western strategic influence in the region. British officials acknowledged that the deal would not proceed without U.S. backing due to the importance of maintaining the shared military facility.
The Diego Garcia base plays a central role in U.S. and UK military operations across the Middle East and Indo-Pacific and has supported missions from the Cold War era through recent conflicts. Ensuring the base’s long-term operational security was a key reason Britain negotiated the agreement with Mauritius in the first place.
Tensions between London and Washington over the deal have been linked partly to wider disagreements over security cooperation and the use of British bases during recent military operations involving Iran. The dispute has added strain to the traditionally close transatlantic relationship between the two allies.
The proposal to return the islands followed years of international pressure on Britain to resolve the sovereignty dispute with Mauritius, including rulings by global legal bodies urging London to end its administration of the territory.
Although the legislation has been shelved for now, UK officials say discussions with both the United States and Mauritius are expected to continue as they seek a possible path forward for the agreement.
